1. Field of the Invention
The present invention relates to a self-propelled vehicle or chassis with swivel-mounted wheel axles, especially for mobile cranes, having a frame which has both at its front and rear ends two wheels or pairs of wheels, of which at least the wheels or pairs of wheels located at one end of the frame are arranged on pivotable axles for steering the chassis, and the chassis having four support legs fitted with foot plates for setting on the ground and with elevating mechanisms for raising and lowering the same, each of the support legs being installed near one of the wheels or pairs of wheels located at one and/or the other end of the frame.
2. The Prior Art
Mobile cranes, especially mobile cranes used for transferring goods within port installations, are more maneuverable and economical than cranes which move on tracks. They do, however, require a roadbed which is appropriately solid and which has been properly prepared for the size and weight of the crane, and they require knowledgeable and experienced crane operators for moving and setting up the crane so as to eliminate, if possible, the danger of damage and accidents.
Often, especially in areas with little industrial development, mobile gantry cranes of conventional construction cannot be used because the freight yards are not in an appropriate condition and sufficiently experienced crane operators are not available.
It is the object of the present invention to create, especially for a mobile gantry crane, a chassis with swivel-mounted axles which, with a smaller technical input as compared to the known steerable chassis can, with a little care, be easily moved and set up in difficult terrain by unskilled crane operators without damage or accidents.